Posterior Research Articles

At the centre of neuronal, synaptic and axonal pathology in murine prion disease: degeneration of neuroanatomically linked thalamic and brainstem nuclei.

AimsThe processes by which neurons degenerate in chronic neurodegenerative diseases remain unclear. Synaptic loss and axonal pathology frequently precede neuronal loss and protein aggregation demonstrably spreads along neuroanatomical pathways in many neurodegenerative diseases. The spread of neuronal pathology is less studied.MethodsWe previously demonstrated severe neurodegeneration in the posterior thalamus of multiple prion disease strains. Here we used the ME7 model of prion disease to examine the nature of this degeneration in the posterior thalamus and the major brainstem projections into this region.ResultsWe objectively quantified neurological decline between 16 and 18 weeks post‐inoculation and observed thalamic subregion‐selective neuronal, synaptic and axonal pathology while demonstrating relatively uniform protease‐resistant prion protein (PrP) aggregation and microgliosis across the posterior thalamus. Novel amyloid precursor protein (APP) pathology was particularly prominent in the thalamic posterior (PO) and ventroposterior lateral (VPL) nuclei. The brainstem nuclei forming the major projections to these thalamic nuclei were examined. Massive neuronal loss in the PO was not matched by significant neuronal loss in the interpolaris (Sp5I), while massive synaptic loss in the ventral posteromedial nucleus (VPM) did correspond with significant neuronal loss in the principal trigeminal nucleus. Likewise, significant VPL synaptic loss was matched by significant neuronal loss in the gracile and cuneate nuclei.ConclusionThese findings demonstrate significant spread of neuronal pathology from the thalamus to the brainstem in prion disease. The divergent neuropathological features in adjacent neuronal populations demonstrates that there are discrete pathways to neurodegeneration in different neuronal populations.

Off-pump transapical neo-chordae implantation.

A 61-year-old female patient presented with isolated pos ter ior mi t ra l l ea f l e t (PML) pro lapse due to degenerative mitral valve (MV). Preoperative transthoracic echocardiography confirmed severe mitral regurgitation (MR) and isolated prolapse of the P2 segment. The patient was in New York Heart Association (NYHA) functional class II to III. Her left ventricular function was good with an ejection fraction of 66%, the tricuspid annular plane systolic excursion (TAPSE) of 25 mm, a mitral annulus of 42 mm, anterior mitral leaflet (AML) length of 29 mm, PML length of 22 mm, vena contracta of 0.7 cm, and effective regurgitant orifice area (EROA) of 1.2 cm. Medical history included right lung surgery via thoracotomy for lung cancer with chemotherapy in 1982, arterial hypertension and status post hysterectomy in 2002.

Effects of dietary NEXT ENHANCE®150 on growth performance and expression of immune and intestinal integrity related genes in gilthead sea bream (Sparus aurata L.)

Gilthead sea bream juveniles were fed different doses (0, 50, 100, 200, 300 ppm) of NEXT ENHANCE®150 (NE) for 9 weeks. Feed gain ratio (FGR) was improved by a 10% with all the doses, but feed intake decreased in a dose dependent manner. The optimum inclusion level to achieve maximum growth was set at 100 ppm. The hepatosomatic index did not vary and only at the highest dose, viscerosomatic and splenosomatic indexes were significantly decreased. No significant changes were found in haematological parameters, plasma biochemistry, total antioxidant capacity and respiratory burst. In a second trial, NE was given at 100 ppm alone (D1) or in combination with the prebiotic PREVIDA® (0.5%) (PRE) (D2) for 17 weeks. There were no differences in the growth rates, and FGR was equally improved for D1 and D2. No significant changes in haematology and plasma antioxidant capacity were detected. The histological examination of the liver and the intestine showed no outstanding differences in the liver, but the number of mucosal foldings appeared to be higher in D1 and D2 vs CTRL diet and the density of enterocytes and goblet cells also appeared higher, particularly in the anterior intestine. A 87-gene PCR-array was constructed based on our transcriptomic database (www.nutrigroup-iats.org/seabreamdb) and applied to samples of anterior (AI) and posterior (PI) intestine. It included 54 new gene sequences and other sequences as markers of cell differentiation and proliferation, intestinal architecture and permeability, enterocyte mass and epithelial damage, interleukins and cytokines, pattern recognition receptors (PRR), and mitochondrial function and biogenesis. More than half of the studied genes had significantly different expression between AI and PI segments. The functional significance of this differential tissue expression is discussed. The experimental diets induced significant changes in the expression of 26 genes. The intensity of these changes and the number of genes that were significantly regulated were higher at PI than at AI. At PI, both diets invoked a clear down-regulation of genes involved in cell differentiation and proliferation, some involved in cell to cell communication, cytokines and several PRR. By contrast, up-regulation was mostly found for genes related to enterocyte mass, cell epithelial damage and mitochondrial activity at AI. The changes were of the same order for D1 and D2, except for fatty acid-binding proteins 2 and 6 and the PRR fucolectin, which were higher in D2 and D1 fed fish, respectively. Thus, NE alone or in combination with PRE seems to induce an anti-inflammatory and anti-proliferative transcriptomic profile with probable improvement in the absorptive capacity of the intestine that would explain the improved FGR.

Pre-plan parameters predict post-implant D90 ≥ 140 Gy for (125)I permanent prostate implants.

PurposeTo find permanent prostate implant (PPI) pre-plan dosimetric parameters that predict post-implant D90 ≥ 140 Gy.Material and methodsPre-plans were evaluated for 504 patients undergoing PPI with 125I seeds for low or intermediate risk prostate cancer. Baseline patient and disease factors, numbers of seeds, ratios of number of seeds to available positions (occupancy proportion), and distances between the 100% isodose line and edge of the prostate (margin) planned for the whole prostate (WP), superior (S), inferior (I), anterior (A), and posterior (P) halves, SA, SP, IA, and IP quarters, and superior (ST), inferior (IT), and middle (MT) thirds, and anterior (AT) and posterior (PT) middle one-sixth segments were analyzed by post-implant D90 subset (≥ 140 Gy vs. < 140 Gy).Results20% had post-implant D90 < 140 Gy (mean: 128.0 Gy, range: 97.5-139.2) vs. ≥ 140 Gy (mean: 154.4 Gy, range: 140.0-193.5). The D90 ≥ 140 Gy subset had larger AT and IA segment mean numbers of seeds (p = 0.01, 0.046), larger WP, S, A, SA, ST, AT, and MT segment mean margins (p = 0.01, 0.01, 0.001, 0.0001, 0.03, 0.005, 0.02), and lower PT segment occupancy proportion (p = 0.004). On multivariate analysis, independent predictors of post-implant D90 ≥ 140 Gy were increased SA mean margin, no pre-implant 5-α-reductase inhibitor, higher pre-plan D90, decreased P occupancy proportion, no pre-implant hormone therapy, and decreased SP mean margin.ConclusionsHigher occupancy proportion and larger margins anteriorly and reduced occupancy proportion, and smaller margins posteriorly on PPI pre-plans predict post-implant D90 ≥ 140 Gy.

Relationship between Lower Extremity Tightness and Star Excursion Balance Test Performance in Junior High School Baseball Players.

[Purpose] The purpose of this study was to examine the relationship between lower extremity tightness and lower extremity balance, measured by the Star Excursion Balance Test (SEBT), in junior high school baseball players. [Subjects] Thirty-three male students belonging to baseball clubs in 2 junior high schools participated in this study. [Methods] For the SEBT, we chose to examine the anterior (ANT), posterior (POS), lateral (LAT), and medial (MED) directions. Regarding muscle tightness measurement, the angle of each joint of the bilateral iliopsoas, quadriceps, hamstring, gastrocnemius, hip internal rotator, and hip external rotator was measured. [Results] The ANT direction of the SEBT was significantly negatively correlated with gastrocnemius tightness. The MED direction of the SEBT was significantly positively correlated with hip internal rotator tightness and hamstrings tightness and significantly negatively correlated with gastrocnemius tightness. The LAT direction of the SEBT was significantly negatively correlated with iliopsoas tightness and gastrocnemius tightness. [Conclusion] Since the rate of upper extremity injury is high in these subjects and this could be due to tightness and instability of the lower extremity from a kinetic viewpoint, the SEBT could be used as a standard evaluation test when examining upper extremity injuries in young baseball players.

Color stability and tenderness variations within the gluteus medius from beef top sirloin butts

Beef top sirloin butts (n=48) from USDA quality grade (QG; upper 2/3 US Choice vs. US Select) and yield grade categories (YG; 1 and 2 vs. 4 and 5) were aged 14days, GM steaks were cut, with 2 steaks removed from the anterior (ANT), middle (MID) and posterior (POST) sections of the GM. One steak from each section was cut into lateral (LAT), central (CENT) and medial (MED) portions, packaged aerobically, and displayed for 7days, whereas the second steaks were cooked to 71°C for WBSF. Top Choice-steaks were redder and more yellow (P<0.05) than Select steaks during display. Cooking losses were greatest (P<0.05) in the MED, and least (P<0.05) in the CENT, portions of GM steaks. Neither QG nor YG category affected WBSF, but differences within the GM were found for (P<0.05) WBSF. Results of this experiment indicate tenderness and color stability gradients exist within the GM.

症例 後下壁の再梗塞後,心電図上の前壁梗塞の所見がほぼ消失した陳旧性貫壁性前壁梗塞の2例

症例 後下壁の再梗塞後,心電図上の前壁梗塞の所見がほぼ消失した陳旧性貫壁性前壁梗塞の2例

Area‐specific substratification of deep layer neurons in the rat cortex

Gene markers are useful tools to identify cell types for fine mapping of neuronal circuits. Here we report area-specific sublamina structure of the rat cerebral cortex using cholecystokinin (cck) and purkinje cell protein4 (pcp4) mRNAs as the markers for excitatory neuron subtypes in layers 5 and 6. We found a segregated expression, especially pronounced in layer 6, where corticothalamic and corticocortical projecting neurons reside. To examine the relationship between gene expression and projection target, we injected retrograde tracers into several thalamic subnuclei, ventral posterior (VP), posterior (PO), mediodorsal (MD), medial and lateral geniculate nuclei (MGN and LGN); as well as into two cortical areas (M1 and V1). This combination of tracer-in situ hybridization (ISH) experiments revealed that corticocortical neurons predominantly express cck and corticothalamic neurons predominantly express pcp4 mRNAs in all areas tested. In general, cck(+) and pcp4(+) cells occupied the upper and lower compartment of layer 6a, respectively. However, the sublaminar distribution and the relative abundance of cck(+) and pcp4(+) cells were quite distinctive across areas. For example, layer 6 of the prelimbic cortex was almost devoid of cck(+) neurons, and was occupied instead by corticothalamic pcp4(+) neurons. In the lateral areas, such as S2, there was an additional layer of cck(+) cells positioned below the pcp4(+) compartment. The claustrum, which has a tight relationship with the cortex, mostly consisted of cck(+)/pcp4(-) cells. In summary, the combination of gene markers and retrograde tracers revealed a distinct sublaminar organization, with conspicuous cross-area variation in the arrangement and relative density of corticothalamic connections.

Body Composition and Physical Function in Individuals with Multiple Sclerosis and Age-BMI Matched Controls

Persons with multiple sclerosis (PwMS) have reductions in physical function compared to healthy peers. In older adults, changes in body composition, specifically adiposity and lean mass, have been linked to reductions in physical function. The relation between body composition and physical function in PwMS is not well established. PURPOSE: The aim of this study was to determine if body composition, specifically a) adiposity (%Fat), b) lean mass of the legs (LEG), and c) leg lean mass to body mass ratio (LEG/BM) impacts lower extremity physical function (LEPF) differently in PwMS compared to controls. METHODS: PwMS (n = 33) and age (47.6±10.8 y) and BMI matched (27.3±6.8 kg/m2) controls (CON; n = 33) were measured for body composition via DXA and LEPF via 6-minute walk (WALK), Timed Up and Go (UPGO) and the Star Excursion Balance Test (SEBT) in the anterior (ANT), medial (MED) and posterior (POST) directions. RESULTS: Although not significant, PwMS had higher %Fat and lower LEG than CON (34.9±7.9% vs. 31.1±10.8%; 15.9±4.0 kg vs. 17.1±3.6kg, both p>0.05). However, LEG/BM was lower in PwMS compared to CON (0.21±0.3 kg vs. 0.23±0.4 kg, p=0.02). For all LEPF tests, compared to CON, PwMS had poorer performance; a 48% slower UPGO speed (4.0±1.0 sec vs. 8.3±5.7 sec, p<0.001), a 39% shorter WALK distance (1540.2±462.0 ft vs. 2136.5±347.9, p<0.001) and reduced reach lengths in the ANT, MED and POST (Right: 11.0%, 12.7%, 31.9%; Left: 7.9%, 22.1%, 32.3%, respectively, all p<0.05). Evaluating median splits for %Fat and LEG/BM, in the absence of any interactions, main effects were determined for: a) %Fat (p=0.01) and Group (p <0.001) such that higher %Fat and MS was associated with shorter WALK distance; and, b) LEG/BM (p = 0.069, p<0.001) and Group (both p<0.001) with a lower ratio and MS being associated with a slower UPGO speed and a shorter WALK distance. CONCLUSION: Comparing PwMS with age and BMI matched healthy controls, the ratio of leg lean mass to body mass was lower with a trend for a higher adiposity; as expected, all LEPF performance was poorer. Importantly, MS status and higher adiposity and lower ratio of leg mass to body mass combine to elicit the poorest LEPF. Body composition may be an important intervention target to preserve function in PwMS. Support: UIUC Research Board (PI: Fernhall)

Obesity Status and Moderate-to-Vigorous Physical Activity Influence Physical Function in Community-Dwelling Older Adults

Aging is accompanied by a progression reduction in lean mass, gains in adiposity, and reductions in physical activity. Similarly, aging is associated with detriments in physical function, including gait and balance. Gaining a better understanding of the influences of body composition and physical activity on physical function is imperative for prevention and treatment of mobility disability. PURPOSE: The primary purpose of this study was to determine the influence of body composition components (adiposity and mineral-free lean mass (MFLM)) and moderate-to-vigorous physical activity (MVPA) on measures of lower-extremity physical function (LEPF) in community-dwelling older adults. METHODS: Older adults (N=156, age=68.9±6.7 years, 85 men) were assessed for adiposity (%Body Fat) and relative muscle mass (Skeletal Muscle Index (SMI); appendicular MFLM/ht2) via dual-energy X-ray absorptiometry, and total and MVPA using accelerometers. LEPF was assessed by 7-m walk tests, a Timed Up and Go (Up&Go), a 30-second chair stand test (30-Chair), a 6-min walk, the Short Physical Performance Battery (SPPB) and the Star-Excursion Balance Test (STAR) in the anterior (ANT), medial (MED) and posterior (POST) directions. RESULTS: Men performed better on all LEPF tests (all p<0.05). Unlike all other independent variables, SMI was not related to any LEPF outcomes. With no significant interactions between %Body Fat and MVPA on gait-related tests (all p>0.25), main effects for adiposity were found for all LEPF, with no main effect of PA. On STAR balance tests, an interaction existed for POST and composite reaches (p<0.05). After accounting for influences of sex, age and total medication usage %Body Fat remained a significant predictor of all LEPF measures. CONCLUSIONS: Our results suggest that adiposity is a major determinant of both balance and gait-related physical function in relatively healthy older adults. Physical activity may help to prevent age-related loss of balance, but appears to be less important than adiposity in relation to mobility.

Spermatogenesis in the blue swimming crab, Portunus pelagicus, and evidence for histones in mature sperm nuclei

Spermatogenesis in the blue swimming crab, Portunus pelagicus, is described by light and electron microscopy . The testis is composed of anterior (AT) and posterior (PT) lobes, that are partitioned into lobules by connective tissue trabecula, and further divided into zones (germinal, transformation and evacuation), each with various stages of cellular differentiation. The vas deferens is classified into three distinct regions: anterior (AVD), median (MVD), and posterior (PVD), on the presence of spermatophores and two secretions, termed substance I and II. Based on the degree and patterns of heterochromatin, spermatogenesis is classified into 13 stages: two spermatogonia (SgA and SgB), six primary spermatocytes (leptotene, zygotene, pachytene, diplotene, diakinesis, and metaphase), a secondary spermatocyte (SSc), three spermatids (St 1–3), and a mature spermatozoon. Spermatid stages are differentiated by chromatin decondensation and the formation of an acrosomal complex, which is unique to brachyurans. Mature spermatozoa are aflagellated, and have a nuclear projection and a spherical acrosome. AUT-PAGE and Western blots show that, during chromatin decondensation, there is a reduction of most histones, with only small amounts of H2B and H3 remaining in mature spermatozoa.

Johne's disease caused by Mycobacterium avium subsp. paratuberculosis infection in red deer (Cervus elaphus): An histopathological grading system, and comparison of paucibacillary and multibacillary disease

AIM: To describe a grading system for evaluating lesions in the small intestine and mesenteric lymph nodes of red deer (Cervus elaphus) infected with Mycobacterium avium subsp. paratuberculosis (MAP), and report the distribution of granulomas and findings seen in paucibacillary and multibacillary forms of the disease. METHODS: Tissues were examined from red deer either experimentally (n=300) or naturally (n=131) infected with MAP. A disease severity score developed previously was expanded to help provide more sensitivity in assessing severity of disease. The distribution of granulomatous, paucibacillary and multibacillary lesions in sections of jejunum, ileocaecal valve and mesenteric lymph nodes was compared between sites and between animals with mild (severity score ≤7) and severe (severity score ≥8) forms of the disease. RESULTS: Based on the results of three published studies, the severity score related well with the clinical severity and gross lesions associated with the disease. Paucibacillary lesions tended to have smaller macrophages and increased numbers of Langhan's giant cells than multibacillary forms, but this was not a consistent finding. The multibacillary form of the disease had Langhan's giant cells, containing numerous acid-fast organisms (AFO), and in one form sheets of epithelioid-like macrophages with prominent vacuolated cytoplasm and few Langhan's giant cells. In deer experimentally infected with MAP, granulomatous lesions were more evident in mesenteric lymph nodes than in intestinal tissue, especially in the mild form of the disease. In mild cases, granulomas were significantly more evident in Peyer's patches than in the intestinal mucosa, but in severe cases, the difference was not significant. Paucibacillary forms of the disease were more evident in deer with the mild disease, and multibacillary forms were more evident in deer with the severe disease. CONCLUSIONS: The severity score provides an objective measure of the severity of Johne's disease, and is useful for comparing individuals and groups of deer in studies involving experimental or natural infection with MAP. In mild disease, lesions were more evident in mesenteric lymph nodes than in jejunum and ileocaecal tissue, and Langhan's giant cells were present in both paucibacillary and multibacillary forms of the disease. The post erior jejunum and ileocaecal-valve lymph nodes were the best sites for detecting mild lesions, while intestinal samples from the posterior jejunum and ileocaecal valve had a lesser but useful role.

Molar furcation entrance and its relation to the width of curette blades used in periodontal mechanical therapy

The purpose of this research was to evaluate molar furcation entrances and the width of periodontal curette blades used in periodontal instrumentation. One hundred extracted molars (50 upper and 50 lower) were analysed. The furcation entrances were measured using orthodontic wires of different predetermined diameters: 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9 mm. McCall 17-18, Gracey 5-6 and Gracey 5-6 mini-five curette blades were measured at their anterior (AT), middle (MT) and posterior (PT) thirds by a single trained investigator, through the use of a digital caliper. The results showed significant differences (P < 0.0001) in relation to furcation entrances. The buccal upper molar furcations showed the narrowest dimensions. In relation to the blade diameter, significant differences among the instruments were found for their MT and PT (P < 0.0001), but not for the AT (P = 0.183). Significant differences were found among curette manufacturers. Nineteen per cent of evaluated furcations presented entrances <0.60 mm and 75% of the blades at their AT presented width >0.60 mm. These findings demonstrated that some molar furcation entrances could not be adequately instrumented with the tested curettes. The use of other hand instruments, such as periodontal files, rotating instruments and ultrasonic devices should be taken into consideration during periodontal therapy.

Multisensory connections of monkey auditory cerebral cortex

Functional studies have demonstrated multisensory responses in auditory cortex, even in the primary and early auditory association areas. The features of somatosensory and visual responses in auditory cortex suggest that they are involved in multiple processes including spatial, temporal and object-related perception. Tract tracing studies in monkeys have demonstrated several potential sources of somatosensory and visual inputs to auditory cortex. These include potential somatosensory inputs from the retroinsular (RI) and granular insula (Ig) cortical areas, and from the thalamic posterior (PO) nucleus. Potential sources of visual responses include peripheral field representations of areas V2 and prostriata, as well as the superior temporal polysensory area (STP) in the superior temporal sulcus, and the magnocellular medial geniculate thalamic nucleus (MGm). Besides these sources, there are several other thalamic, limbic and cortical association structures that have multisensory responses and may contribute cross-modal inputs to auditory cortex. These connections demonstrated by tract tracing provide a list of potential inputs, but in most cases their significance has not been confirmed by functional experiments. It is possible that the somatosensory and visual modulation of auditory cortex are each mediated by multiple extrinsic sources.

Vitrectomy combined with extraction of foreign body by pos terior route for foreign body in the posterior pole segment wall of the globe

目的 探讨后极部视神经附近磁性异物的手术方式及效果.方法 对15例(15眼)眼球穿孔伤或眼球贯通伤后极部或视神经附近磁性异物,行玻璃体切除术联合异物后径摘出术,根据术中具体情况行眼内光凝、硅油或全氟化碳(C3F8)填充.结果 15例异物全部一次手术摘出成功.术后所有患眼视力均有不同程度的提高,无视网膜脱离等并发症发生.结论 玻璃体切除术联合磁性异物后径摘出术是治疗眼球穿孔伤或眼球贯通伤玻璃体积血合并后极部视神经附近磁性异物的一种可靠方法。

Cheilopogon olgae (Exocoetidae)—A new species of flying fish from the waters of Western Australia

271 As early as 1962, when performing integrated oceanological studies on the 35th cruise of R/V Vityaz (information on the cruise see Kuznetsov and Parin (1964) in the eastern part of the Indian Ocean off the coast of Australia between 20° and 34° S, several spec imens of flying fish (Exocoetidae) were caught that obviously belonged to the undescribed species of the genus Cheilopogon (subgenus Ptenichthys) which dif fered in the presence of a large black spot on the pos terior part of ventral fins in adult specimens. Twenty five years later (1987–1989) in the same area, works were performed by the Japanese tuna catching vessel Shoya maru. Ichthyologist Dr. Izumi Nakamura par ticipated in these cruises; he collected a very represen tative collection of fish of this species that is kept at the present time in the Museum of Kyoto University (FRSKU, Maizuru) and, partially, in Australian museums (AMS, WAM, etc.). This collection was examined by the author of the present paper during visits to Australia (1988) and Japan (1992). This col lection also contained specimens of the new species considered here.

Left Atrial Fibroma in Gardner Syndrome

Left Atrial Fibroma in Gardner Syndrome

Power Isn’t Everything: Muscle Function and Energetic Costs during Steady Swimming in Atlantic Cod (Gadus morhua)

Power produced by red myotomal muscles of fish during cruise swimming appears seldom maximized, so we sought to investigate whether economy may impact or dominate muscle function. We measured cost of transport (COT) using oxygen consumption and the strain trajectories and electromyographic activity of red muscle measured at anterior (ANT) and posterior (POST) locations while Atlantic cod (Gadus morhua) swam steadily at speeds between 0.3 and 1.0 body lengths (BL) s(-1). We then measured the power produced by isolated segments of red muscle when activated either as in the swimming cod or such that maximal net power was produced. Patterns of activation during swimming were not optimal for power output and were highly variable between tail beats, particularly at the ANT location and at slow swim speeds. Muscle strain amplitude did not increase until swimming speed reached 0.9 (ANT) versus 0.5 (POST) BL s(-1). These limited power to only 53% (ANT) and 71% (POST) of maximum at slower swim speeds and to 70%-80% of maximum at high swim speeds. COT (resting metabolism subtracted) was minimal at the slowest swim speed, surprisingly, where power was most impaired by activation and strain. Thus, production of powered forces for maneuverability/stability appeared to greatly impact red muscle function during cruise swimming in cod, particularly at slow speeds and in ANT muscle.

Comparing the composition of leg muscles in young, old, and very old men

Cross‐sectional studies report varying degrees of muscle atrophy in different muscles but usually involve the comparison of one young with one old age group. Using serial sections obtained by MR imaging, the cross‐sectional areas (CSA) of contractile and non‐contractile tissues in the anterior (ANT), lateral (LAT), and posterior (POST) compartments of the leg were measured in 38 men with ages averaging in their 3rd, 7th or 9th decades (young, old, and very old, respectively). Tissue type and compartment borders were distinguished visually and traced manually. Contractile CSA for each compartment was similar between the young and old groups, but was significantly reduced between 15–28% for all compartments in the very old. There was a significant increase in the non‐contractile tissue in all compartments across the age groups which were 1–5% from young to old and a further 5–10% between the old and very old. The greatest change was observed in the POST compartment and the smallest change in the ANT compartment. With two groups of older adults, these data demonstrate that skeletal muscle CSA in the leg is moderately well preserved until about 65y of age when there is an increased rate of deterioration. Previous studies have not compared changes in these 3 compartments of the leg. It is clear that not all muscles show similar degrees of age‐related changes which likely has functional implications.

OC116: Trocar‐assisted selective laser photocoagulation of communicating vessels

Objectives: Selective laser photocoagulation of communicating vessels (SLPCV) for twin–twin transfusion syndrome (TTTS) in patients with an anterior (ANT) placenta is known to be technically more challenging than in patients with posterior (POST) placentas. We describe a new trocar-assisted (TA) technique to address this issue. Methods: Four surgical techniques were used for SLPCV in ANT placentas: standard, rigid scope; flexible scope; side-firing, twoport; and TA, whereby the anastomoses were lasered from within the trocar sheath after identification with an angled diagnostic endoscope. The protocol was approved by the Institutional Review Board and all patients signed informed consent. Results: SLPCV was performed in 269 patients from February 2003 to May 2005, of which 88 (47.6%) had ANT placentas. Only 7/88 (7.9%) patients with ANT placentas were treated with a flexible scope or a two-port technique and neither of these techniques was used after November 2003. Perinatal survival was independent of placental location (89.7% vs. 85.2%, POST vs. ANT placentas) or ANT placenta techniques. Gestational age at delivery (median 33.1 (range, 17.6–39.4) weeks), and incidence of premature rupture of membranes within 21 days of surgery, was no different between techniques in patients with ANT. However, operating time was significantly less in the TA group (P < 0.05). In 50/88 patients with ANT placentas available for analysis, only one had patent anastomoses in the TA group (2.9%), compared to none in the other techniques (P = 0.7). Conclusions: Laser treatment of TTTS patients with an ANT placenta that requires more than a simple rigid endoscope can be effectively achieved with a TA technique. TA allows orthogonalization of the angle of fire, eliminating the need for a two-port or flexible endoscope technique. TA is also useful in exposing the entire vessel wall in patients with POST placentas with a tangential angle of entry.